Parasaurolophus lived at the end of the cretaceous period, about 76,5-73 million years ago in the area that today is America. Similar to other dinosaurs in the group known as the hadrosaurs Parasaurolophus could walk on both two and four legs. It is believed it preferred to walk on for legs when looking for food, and on two when it had to run or move fast.
There were different species of parasaurolophus that had cranial crests of different lenght. Researchers have had many different ideas over the years of what exactly the cranial crest was used for. Some even believed it was used as a snorkel! Today we believe the cranial crest was used as a resonance chamber for sound when parasaurolophus communicated with each other, as well as for showing off and attracting a mate.